电主轴动态特性分析及结构优化

Dynamic characteristic analysis and optimization design of the electric spindle

以某高速数控车削中心的电主轴为研究对象,建立了电主轴的有限元模型。以等效弹簧单元来模拟轴承对电主轴的支承刚度,同时将电动机转子部分视为分布质量单元附加在电主轴的相应安装位置。对电主轴有限元模型进行了动态特性分析,获得了各阶固有频率及振型。通过LMS模态测试设备对电主轴进行模态测试,测试结果与有限元计算结果的误差在10%以内,验证了此有限元模型的正确性。最后,在有限元模型的基础上进行了轴承支承跨距的优化分析,提高了电主轴的固有频率。

One kind of finite element modeling methods for the electric spindle was studied. Simulation of bearing supporting stiff- ness for electric spindle with some spring elements, at the same time, the motor stator part as the distributed mass unit attached to respective mounting position of spindle. Based on the finite element mode, dynamic characteristics of the electric spindle was ana- lyzed, and each order natural frequency and vibration mode map were obtained. By comparing the LMS modal test data and the simulation results show that errors was within 10% ,which proved the validity of the finite element model. Finally, based on the fi- nite element model, a optimization analysis of bearing support span was carried out, which improved the natural frequency of the electric spindle.